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Almost Union-Find 并查集的删除
Almost Union-Find
I hope you know the beautiful Union-Find structure. In this problem, you‘re to implement something similar, but not identical.
The data structure you need to write is also a collection of disjoint sets, supporting 3 operations:
1 p q
Union the sets containing p and q. If p and q are already in the same set, ignore this command.
2 p q
Move p to the set containing q. If p and q are already in the same set, ignore this command
3 p
Return the number of elements and the sum of elements in the set containing p.
Initially, the collection contains n sets: {1}, {2}, {3}, ..., {n}.
Input
There are several test cases. Each test case begins with a line containing two integers n and m (1<=n,m<=100,000), the number of integers, and the number of commands. Each of the next m lines contains a command. For every operation, 1<=p,q<=n. The input is terminated by end-of-file (EOF). The size of input file does not exceed 5MB.
Output
For each type-3 command, output 2 integers: the number of elements and the sum of elements.
Sample Input
5 7 1 1 2 2 3 4 1 3 5 3 4 2 4 1 3 4 3 3
Output for the Sample Input
3 12 3 7 2 8
Explanation
Initially: {1}, {2}, {3}, {4}, {5}
Collection after operation 1 1 2: {1,2}, {3}, {4}, {5}
Collection after operation 2 3 4: {1,2}, {3,4}, {5} (we omit the empty set that is produced when taking out 3 from {3})
Collection after operation 1 3 5: {1,2}, {3,4,5}
Collection after operation 2 4 1: {1,2,4}, {3,5}
Rujia Liu‘s Present 3: A Data Structure Contest Celebrating the 100th Anniversary of Tsinghua University
Special Thanks: Yiming Li
Note: Please make sure to test your program with the gift I/O files before submitting!
ac代码:
#include<stdio.h> int f[200005],id[200005],c[200005],sum[200005]; int dex; int find(int x) { return f[x]==x?x:f[x]=find(f[x]); } void join(int x,int y) { int fx=find(x),fy=find(y); if(fx!=fy){ f[fy]=fx; c[fx]+=c[fy]; sum[fx]+=sum[fy]; } } void del(int x) { int fx=find(id[x]); c[fx]--; sum[fx]-=x; id[x]=++dex; f[dex]=dex; c[dex]=1; sum[dex]=x; //并查集删除操作 } int main() { int n,q,x,y,z,i; while(~scanf("%d%d",&n,&q)){ dex=n; for(i=1;i<=n;i++){ f[i]=i; id[i]=i; c[i]=1; sum[i]=i; } for(i=1;i<=q;i++){ scanf("%d",&x); if(x==1){ scanf("%d%d",&y,&z); join(id[y],id[z]); } else if(x==2){ scanf("%d%d",&y,&z); int fy=find(id[y]); int fz=find(id[z]); if(fy!=fz){ del(y); join(id[y],id[z]); } } else{ scanf("%d",&y); int fy=find(id[y]); printf("%d %d\n",c[fy],sum[fy]); } } } return 0; }
Almost Union-Find 并查集的删除